The method java.lang.Object.equals()
, by default, is unable to compare composite objects such as cryptographic keys. Most Key
classes do not fail to provide an equals()
implementation that overrides Object.equals()
. In such cases, the components of the composite object must be compared individually to ensure correctness.
Noncompliant Code Example
This noncompliant code example compares two keys using the equals()
method, but the . The keys may compare unequal even if when they represent the same value.
Code Block | ||
---|---|---|
| ||
private static boolean keysEqual(Key key1, Key key2) {
if (key1.equals(key2)) {
return true;
}
return false;
}
|
Compliant Solution
This compliant solution uses the equals()
method as a first test and then compares the encoded version of the keys to facilitate provider-independent behavior. For example, it can be checked if a It checks whether an RSAPrivateKey
and an RSAPrivateCrtKey
represent an equivalent private key keys [Sun 2006Oracle 2011b].
Code Block | ||
---|---|---|
| ||
private static boolean keysEqual(Key key1, Key key2) { if (key1.equals(key2)) { return true; } if (Arrays.equals(key1.getEncoded(), key2.getEncoded())) { return true; } // More code for different types of keys here. // For example, the following code can check ifwhether // an RSAPrivateKey and an RSAPrivateCrtKey are equal: if ((key1 instanceof RSAPrivateKey) && (key2 instanceof RSAPrivateKey)) { if ((((RSAKey) key1).getModulus().equals(((RSAKey) key2).getModulus())) && (((RSAPrivateKey) key1).getPrivateExponent().equals( ((RSAPrivateKey) key2).getPrivateExponent()))) { return true; } } return false; } |
Automated Detection
...
Tool | Version | Checker | Description | ||||||
---|---|---|---|---|---|---|---|---|---|
The Checker Framework |
| Interning Checker | Errors in equality testing and interning (see Chapter 5) |
Bibliography
[API |
...
2013] |
...
java.lang.Object.equals() , Object.equals() | |
[Oracle 2011b] | Determining If Two Keys Are Equal (JCA Reference Guide) |
...
MSC03-J. Never hardcode sensitive information 49. Miscellaneous (MSC) MSC05-J. Store passwords using a hash function